1. Field of the Invention
The invention relates to a semiconductor device and a method of manufacturing the same, particularly to an optical sensor which measures a position of an object by irradiating the object with light from a light emitting portion and sensing the reflected light by a light receiving portion, and a method of manufacturing the same.
2. Description of the Related Art
An optical sensor is known as one of means of measuring a position of an object. This optical sensor has a light receiving portion and a light emitting portion, and detects a position of an object to be measured by, for example, irradiating the object with an optical pulse by the light emitting portion, sensing the luminance or phase of the optical pulse reflected by the object by the light receiving portion, and using the difference between the luminances or phases of both the optical pulses.
For example, such an optical sensor is applied to a technology of automatically sensing a distance between a user and a sound collecting microphone of a mobile and optimizing the phone volume according to the distance. In this technology, the optical sensor is provided near the sound collecting microphone of the mobile, and the luminance or the like of reflected light of light emitted to the user by the light emitting portion of the optical sensor is measured by the light receiving portion of the optical sensor, thereby measuring the distance between the user and the sound collecting microphone.
When such an optical sensor is realized by a semiconductor device, as shown in FIG. 12, a light receiving die (i.e. a semiconductor die) 101 including a light receiving element such as a photodiode is mounted as the light receiving portion on an elongated rectangular mounting substrate 100, and a light emitting die (i.e. other semiconductor die) 102 including a light emitting element such as an LED is separately mounted thereon as the light emitting portion.
An optical sensor for detecting a position of an object to be measured is described in Japanese Patent Application Publication No. 2001-183458.
In the optical sensor described above, however, since the light receiving die 101 and the light emitting die 102 are mounted on the mounting substrate 100 as separate semiconductor dies, it is necessary to secure a wide mounting region. This makes it difficult to reduce the size of the optical sensor.